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implement Chmod;
include "sys.m";
include "draw.m";
include "string.m";
Chmod: module
{
init: fn(ctxt: ref Draw->Context, argv: list of string);
};
sys: Sys;
stderr: ref Sys->FD;
str: String;
User: con 8r700;
Group: con 8r070;
Other: con 8r007;
All: con User | Group | Other;
Read: con 8r444;
Write: con 8r222;
Exec: con 8r111;
usage()
{
sys->fprint(stderr, "usage: chmod [8r]777 file ... or chmod [augo][+-=][rwxal] file ...\n");
raise "fail:usage";
}
init(nil: ref Draw->Context, argv: list of string)
{
sys = load Sys Sys->PATH;
stderr = sys->fildes(2);
str = load String String->PATH;
if(str == nil){
sys->fprint(stderr, "chmod: cannot load %s: %r\n", String->PATH);
raise "fail:bad module";
}
if(len argv < 3)
usage();
argv = tl argv;
m := hd argv;
argv = tl argv;
mask := All;
if (str->prefix("8r", m))
m = m[2:];
(mode, s) := str->toint(m, 8);
if(s != "" || m == ""){
ok := 0;
(ok, mask, mode) = parsemode(m);
if(!ok){
sys->fprint(stderr, "chmod: bad mode '%s'\n", m);
usage();
}
}
ndir := sys->nulldir;
for(; argv != nil; argv = tl argv){
f := hd argv;
(ok, dir) := sys->stat(f);
if(ok < 0){
sys->fprint(stderr, "chmod: cannot stat %s: %r\n", f);
continue;
}
ndir.mode = (dir.mode & ~mask) | (mode & mask);
if(sys->wstat(f, ndir) < 0)
sys->fprint(stderr, "chmod: cannot wstat %s: %r\n", f);
}
}
parsemode(spec: string): (int, int, int)
{
mask := Sys->DMAPPEND | Sys->DMEXCL | Sys->DMTMP;
loop: for(i := 0; i < len spec; i++){
case spec[i] {
'u' =>
mask |= User;
'g' =>
mask |= Group;
'o' =>
mask |= Other;
'a' =>
mask |= All;
* =>
break loop;
}
}
if(i == len spec)
return (0, 0, 0);
if(i == 0)
mask |= All;
op := spec[i++];
if(op != '+' && op != '-' && op != '=')
return (0, 0, 0);
mode := 0;
for(; i < len spec; i++){
case spec[i]{
'r' =>
mode |= Read;
'w' =>
mode |= Write;
'x' =>
mode |= Exec;
'a' =>
mode |= Sys->DMAPPEND;
'l' =>
mode |= Sys->DMEXCL;
't' =>
mode |= Sys->DMTMP;
* =>
return (0, 0, 0);
}
}
if(op == '+' || op == '-')
mask &= mode;
if(op == '-')
mode = ~mode;
return (1, mask, mode);
}
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